Dyeing of textiles



Patented July 5, 1938 UNITED stares PATENT OFHQE No Drawing. Application .lluly Ill, 1933, Serial No. 679,890. in Germany .luly 12, 1932 4 Claims.

The direct dyeing of the vegetal as well as of the animal fibre with water-soluble dyestuffs is the simplest of all dyeing methods and at the same time the most harmless one for the fibre. There is, however, the disadvantage of a more or less remarkable lack of fastness of the dyed materials to water and washing. Though there are in the prior art a great number of processes to overcome this deficiency, these processes take, however, a certain constitution of the dyestuff for granted, their performance is in many cases rather complicated and none of them leads to a perfect washing-fastness such as is attainable by means of the vat-, sulphurand ice-colours.

Now a process has been found which permits one to render more or less fast to Washing any direct-dyeing performed on'fibres of natural or regenerated cellulose. This process differs principally front the usual methods of increasing f astness in so far as the effect is not obtained by augmenting the molecule by adding water-insoluble residues to the dyestuif molecule, but by rendering ineffective the groupsin general sulphoor carboxyl groups-which bring about the watersolubility of the dyestufi and consequently its unfastness. This is obtained by forming salts which are absolutely insoluble and also resistant against the reaction of acids and alkalis as well as against soap. The quaternary ammonium bases containing a system of no less than 8 non-interrupted conjugateddouble bonds, possessing substantive properties, have been recognized as eminently fit for the forming of such insoluble salts. These conjugated double bonds may belong either to open chains or to ring systems which may seem to be interrupted by imino groups in which cases I assume that, for instance, the-group CONH acts in the enolic form ---C(OH)Y=N., so that really no interruption of double linkings occurs. The new process consists therefore in the following: one begins with a direct dyeing on the fibre in the usual manner, whereupon the preliminarily dyed fibre is treated, with or without an intermediate rinsing, in a second bath with the solution of a salt of the quaternary ammonium base which forms an insoluble salt; then one rinses, one soaps once more should it be necessary, one rinses again and finally one dries. If the dye is extracted completely or almost completely from the dyeing bath, it is permissible. to add directly to the exhausted dye bath also the ammonium base. It is not necessary that the quaternary ammonium base be colourless, but it may also be of a dyestuif character so that it'is able to intensify the dying or to shade it off or to alter it completely.

This special embodiment of the present process oflers the advantage that for the obtainment of a predetermined colour intensity one needs dyestuffs in c'omparison with the amount required for an ordinary direct dyeing; in consequence of which the dyestuff is extracted from the bath relatively more intensively or even completely so that the aforementioned simple singlebath-procedure will be applicable.

From the experiments so far made it was discovered that substantive quaternary ammonium bases-with at least two quaternary ammonium groups are particularly capable of making organic compounds of an acid character fast to washing on the cellulose fibre.

The aforedescribed after-treatment is of a prime importance for the mordant-drawing direct cotton dyestuffs because the dyed material can thus be mordanted and rendered fast to washing in one and the same bath.

Further it has been stated, that it is also practicable to proceed inversely by treating the fibre first with the solution of the substantive quaternary ammonium base and after that with the dyestuif solution without its making any difference whether the ammonium base is colourless with the result that it serves so to speak merely as a mordant for the dyestuff to be laid upon, or whether it also has colouring properties. Under certain circumstances it is not necessary that the dyestuif itself possesses any aflinity for the fibre and the former willnevertheless be fixed .upon the latter though it will not be fast to washing. From this precedure there results the valuable practical procedure of tinging for instance the vegetal fibre after a preliminary treatment with a substantive, basic mordant of the above characterized sort, with so-called acid wool dyestuffs, which are not substantive or only to a little degree, while in many cases they distinguish themselves from the really substantive dyestuffs by cheapness and higher fastness to light.

If the ammoniumbase be at the same time a dyestuif, it is not necessary that the acid component be likewise a dyestuff and it may therefore be represented by any higher molecular organic compound of an acid character, in which instance it is the chief consideration that the latter forms an insoluble salt with the base. In certain cases it is advantageous if it possesses an ailinity for the fibre such as is known for instance of certain sulphurized phenols. Substituted or non-substituted carbonic or sulphonic acids of the allphatic, alicyclic, aromatic or fatty aromatic series are here likewise to be considered. Besides the dyeing effects it is possible to obtain at the same time a further refining effect consisting in rendering the textile goods supple, of a soft handle and of a water repelling property and with artificial silk one obtains certain matting effects, provided that as acid components one chooses soap forming carbonic or sulphonic acids, sulphonated fats and oils or higher molecular fatty alcohol sulphonates. Merely the latter refining effects are obtained if one combines a colourless, substantive ammonium base with the just named carbonic or sulphonic acids etc., whereby it is of course also practicable to replace part of the components by dyestufls and thus to accomplish in one and the same operation the dying and the further refining.

As acid components one may also employ natural or artificial tanning principles, either alone or together with acid dyestufis. In this case it is of a practical interest to employ natural tanning principles of the pyrogallolor ellagene tannic acid category. It is already known that these tanning principles, by an after-treatment on the fibre with copperand chromium salts, produce khaki-shades of an excellent fastness to light, while their fastness to washing can now be increased in the desired manner by adding the salt of a suitable substantive quaternary ammo-'- nium base in the same way as above described for mordant-drawing dyestufls. As acid components there are .finally to be considered the above mentioned substantive compounds obtainable by sulphurizing of phenols and known for instance under .the name of katanoles".

It has already been suggested to render the direct dyeing on the fibre fast to water and wet-ironing and in certain cases evenfast to after-dyeing by an after-treatment with amines or ammonium bases containing a high molecular fatty acid residue. This process produces, however, no fastness to washing and merely a quite imperfect improvement.

Example 1 and by combination of the thus formed monoazo dyestuif in alkaline solution with 1 molecule of diazotized tolusafranine (Schultz-Julius, l. c. Nr. 679). Then one heats up to 95100 C. and keeps thistemperature for 25 to 30 minutes, whereupon one rinses and dries. As a result a very good black dyeing fast to washing is obtained.

Example 3 Cotton is dyed under usual conditions with 1% of benzo-light-blue FR (cf. Fierz-David, Grundlegende Operationen der Farbenchemie, 1922, p. 147) from a neutral bath containing common salt. The dyestufl having completely been drawn on the fibre, one adds immediately and in the form of a hot concentrated solution 1.5% of the reddish blue, substantive dyestufl prepared by diazotizing and coupling of 2 molecules of tolusafranine with 1 molecule of a-naphthol; the bath is kept at boiling temperature until the second dyestuif is likewise drawn on entirely or almost entirely, whereupon one rinses and dries. The thus obtained blackblue dyeing is of an excellent fastness to washing and light.

Example 4 Cotton or viscose-artificial silk is worked for 45 minutes and at -100 C. in a bath which in a bath-length of 1.: 15 contains 2% of an ammonium salt of the following constitution:

further 5% of acetic acid and 20% of common salt. Then one washes cold, whereupon the material while moist is brought into a dyeing bath at a temperature of 60 C. containing 1% of Orange II (Schultz-Julius, l. c. Nr. 145) or of another acid wool dyestufl and 20% of common salt in a bath-length of 1:20. The dyeing bath will be exhausted in a short time.

The above substantive ammonium base can be obtained in the following manner: p-aminodimethyl-aniline is condensed in pyridine solution with 1 moi. of p-nitrobenzoyl chloride. Dimethylsulphate is added to the condensation product CH: 04 whereupon it is taken out, rinsed and dried. The thus obtained tone which compared with the original dyeing shows a more yellowish shade, shows an excellent fastness to washing when treated for half an hour in a 0,2% soap solution at -100 0., whereas the original dyeing will under the same conditions heavily bleed out into the soap bath and in a great part is drawn or! from the fibre.

The above mentioned base is obtained by coupling tetrazotized benzidine with dimethylaniline and addition of dimethylsulphate to the azodyestuff in a nitrobenzol-solution at about -150 C. The methylsulphuric salt is yellow, very easily soluble in water and hygroscopic.

Example 2 whereupon one reduces the nitro group to the amino group and the thus obtained intermediate product is condensed with chloride of cinnamic acid in presence of acid binding stuffs. It is also practicable and advantageous to condense 2 mols of the intermediate product by means of 1 mol. of phosgene or terephthaloylchloride in a pyridine solution.

If one substitutes a substantive basic dyestufi? with one or more quaternary ammonium groups (cf. e. g. the German Patents 93,499 and 97,244) for the substantive ammonium base one obtains the practicability of producing many difi'erent colour tones in combining both colours of the basic and of the acid dyestuff (cf. the following example).

If one chooses as acid dyestufi an alterchromatable one, the aiter-chromating can be done in a third bath ,or immediately in the acid dyeing bath.

Example 5 Cotton or viscose silk is brought at about 60 C. into a dyeing bath (bath-length 1:10 to 1:15) containing 2% of a substantive, basic dyestufl obtainable by the. coupling of 2 mols of diazo- Cotton is worked for 1 hour at 85 C. in a bath (in a bath-length of 1:15)containing 1% of the compound according to the following formula:

further 1% of soda and 20% 01 sodium sulphate. Then one rinses cold, whereupon an after-treatment of half an hour takes place in a warm bath of 1% of the disazo dyestuilf of tetrazotlzed benzidine and 2-oxynaphthyl-7-trimethylammonium chloride (cf. German Patent 90,310), 2% of acetic acid and 10% of common salt.

The above acid and substantive mordant is obtainable by condensing 1,5-naphthylenediamine-3,7-disulphonic acid sodium with the chloride. of cinnamic acid in presence of an acid binding agent. It may be replaced with good results by the products which are obtained by the sulphurizing of phenols (katanol).

Example 7 1% of the dyestuff obtainable by the coupling of tetrazotized dianisidine with 2-oxynaphthyl- 'i-trimethyl-ammonium chloride (of. German Patent 90,310) jointly with 4% of the substantive basic mordants" mentioned inExample 4, is dyed on cotton' or viscose silk as indicated therein. An after-treatment takes place in a hot bath containing 2 g. of sodium laurylsulphonate per litre. The thus dyed material is of a soft and agreeable handle.

Instead of the sodium lauryl-sulphonate one can likewise apply sodium cetylor octadecylsulphonate or Turkey red oil or the sulphuric acid ester salts of the dodecyl-, tetradecyl-, cetylor octadecyl-alcohol or compounds with .similar properties such as oleyltaurin.

(G bb-N cm 0, Example 8 The dyeing is then of a dark bluishblack and eminently fast to washing and light.

Example 9 Cotton clothis workedfor 1 hour-at C. with 10% of a tannin extract of the pyrogallolor ellagene tannic acid category such as myrobalan-, dividivior mango-leaves extract, in a bathlength 01' 1:15. Then one squeezes off and without an intermediate rinsing. the material is brought into a development bath at 60 0. containing 2,5% of the disazoammonium base as per Example 1, in a bath-length of 1:15. After digesting at ail- C. until the ammonium base is completely taken up one adds 2,5% of sodium bichromate and 2,5% of copper vitriol, then one gently agitates for 20 minutes at 80-90 0., whereupon one cools and rinses. There results a khaki-dyeing of an excellent fastness to light and washing.

Example 10 3% of the dyestufl employed'in Example 3 composed of diazotized tolusafranine and anaphthol are dyed on cotton while boiling for about V of an hour and with an addition of 3% of acetic acid and 20% of common salt. Then one cools down to about 40 C. under continuous agitation, at this temperature one adds 10% of tannin extract (myrobalan, dividivi, mango leaves extract) dissolved in a small amount of hot water, whereupon one heats to obtain re-boiling. After about half an hour one takes the cotton out of the bath and develops the dyeing for 25-30 minutes at 80-100 C. in a fresh bath containing 2% of bichromate oi. potassium, 2% of acetic acid and 2% of copper sulphate in a bath-length of 1:20.

There results a dark bluish-black dyeing of an excellent fastness to washing and light.

What I claim is:

1. A process for dyeing cellulosic fibers which comprises producing on the fiber an insoluble salt of a substantive dyestufl and a substantive quaternary ammonium base containing at least two quaternary ammonium groups and a system of no less than 8 conjugated non-interrupted double linkings in its molecule, whereby dyeings fast to washing are obtained.

2. A process for dyeing cellulosic fibers which comprises dyeing the fiber by means of a substan-v tive dyestufl and after-treating the dyeing thus obtained with the solution of a substantive quaternary ammonium base containing at least two quaternary ammonium groups and a system of no less than 8 conjugated non-interrupted double linkings in its molecule, whereby dyeings fast to washing are obtained.

3. A process for dyeing cellulosic fibers which comprises dyeingthe fiber by means of a substantive dyestuif andafter-treating the dyeing thus obtained with the solution of a substantive disazonium base of the formula:

whereby dyeings fast to washing are obtained.

4. The process for dyeing cellulosic fibres which comprises dyeing the fibre by means of a substantive dye-stuff and after-treating the dyeing thus obtained with the solution of an ammonium salt of the formula:

OCHI whereby dyeings fast to washing are obtained. 

